edition of the same in 4 volumes in German. Other useful manuals are: (1) A Key to Precious Stones by L. J. Spencer; (2) Gems and Gem Materials by Krauss and Slawson; (3) Gem-stones by H. G. Smith. The Journal of the Gemmological Society of London is
a useful one which contains valuable contributions. But there are not
many recent publications on Indian gem-stones. But it may be mentioned
that one of the most valuable Indian publicaÂtions is Mani-Mala, a
treatise on gems by Raja Sourindra Mohun Tagore, published in 1881,
which contains a wealth of information on precious stones. But the book
is out of print and not available to many. All these books are of great
use to students of gemmology.
Gemmology
That
part of mineralogy which is specially useful for the study of gems is
now being called 'Gemmology' in western countries. People specialize in
gemmology and there is a journal of gemmology in England and America.
Some knowledge of Mineralogy and Chemistry are also helpful to
understand the technique of the manufacture of synthetic gems.
The
first nine chapters of this book deal with the elementary facts of
Mineralogy requisite and provide a scientific background for a detailed
study of the gem materials.
Chapter II
HOW GEM-STONES OCCUR AND HOW THEY ARE WON
GEM-STONES
have been found in the oldest of geological formations known as the
Archaeans—formed long before the advent of life and perhaps dating back
to a thousand million years. But it does not follow that they occur
always in the Archaeans and everywhere in them. Gem-stones
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